Please advise steps can be taken to bring about change in attitude of a narcissistic nature.

I'm working with children 9 - 10 years and 3 of them think they are the cat's whiskers. these boys and girls are so rude towards others that they are downright arrogant and openly hostile to those less fortunate than them. there is no discipline issue - they do their tasks and fair quite well - i just want them to be more tolerant.